Rotary hook or loop taker for sewing machines



Jan. 30,1923.

J. LEATHM 1,443,418.

ROTARY HOOK 0R LOOP TAKR FOR SEWING MACHINES. FILED DCL 23, I920.

I I I I run at very high speeds.

Patented dan. .'50, 192th g inane y funirnnsra'rss Param @Wma y "JAMES Lna'rnnivi, or LEBANON, rEnnsYmarmfl; A

` 'ROTARY Hoon on Loor Tanna non snwino lanci-amas.

Application 1edi0ctoberf23, 1920. Serial No. 418,949.

To, all whom t may concern.'

i Be 1t known thatl, Jarras Lna'rnnai, citizen of the Unitedtitates, and a resident of Lebanon, inthe county oi? Lebanon and The accompanying drawings illustrate one embodiment ot' invention, in the se veral 'figures of which like parts are simiF larly designated; y

ln the drawings: i

Figure l is a top view of a rotary hook or loon takerl together with its bobbin case fand bbbbin 'madein accordance with the present invention the drawing being` on an enlarged scale for clearness oit illustration.` Figure 2y is a sectional view on the line 2-2 `oit Figurel` the 'drawing being on a lgreater scale than Figure 'l 'for clearness oi illust ationy Figure is a top `shown in Figure l.

Figure l is a side view ot the bobbin case shown in Figures l and n Figure 5 is a sectional View of the bobhin case on the line of Figure Figure 6 is a top view 01"' the hook.

Figure 7 a `bottom view et the hook.

i Figure a side view otv the hook.

Figure Si is a sectional View ot' the hook on the line QW?) of Figure (i.

Figure l() is a side view of' the key.

"ln the drawings l designates a rotary hook 'or `loop-taker ot a lock stitch sewing umchine mechanism, preferably made inmie piece and provided withfa beak 2 formed adjacent a beak recess 3; ln the present instance the'rotary hook is provided with a circular outer flange llhaving on its inner side adjacent the topr thereot` a circular groove or raceway 5 which is' arranged to rotatably engage a, circular bobbin case Aflange 6 made integral with a bobbin case i view oit the bobbin case `ln the present instance the hook flange a is integrally securedto the base oiE the hook at that portion of the hook flange ininiediately adjacentthe beakQ, as shown in Figure 9? the r Dining* portions oit' ythe hook i'lange beingy cut away "from `the base ot' the hook to permit the tree end off 'the hook flange opposite the beakto be sprung i' out to admit the bobbin case flange 6 oir `the bobbin case into the raceway 5, as shown in Figure 2; i v "I he 'itree end ot the hook flange while sei, arated trom the base of the hook ypreferably rests upon vthe same, shown in Figures 2 and 8, to eerniitoi suitable set screws 8 being usedtoirinly hold the tree* end ot the hook flange in position against `the bas-e of the hookatter the bobbin-f-case has been inserted. I i t i i y The base of the hook is preferably pro- `vided with a circular helen?) situated be-` neath the lree yend of the hooi-change, in the ypresent instancebetweenthe two screws having a roundportion 13 arranged to lit the circularhole 9, the pin ll being set cccentrically on the round portion 13 or the key so that it will act when turned toy torce the :tree end of the hook flange outward, when the set screws'S havebeen removed to permit of the easy removal or insertion ot the'bobbincase.l 7 v The bobbin icase 7 is a hollow cylindrical member, made in one piece, and having ar centrally located post '14 adapted vtoV receive a bobbin 15." ln the present instance-'the bob-bin case is provided with the usual lug l ttor engagement with a ixed part ot the sewing machine whcreliy rotation ot' the bobbin-case is prevented, The bobbin case liange 6 on both sides of the lug); i6 is cut away to permit of the. beak 2 as it engages the bight or loop of the needle thread Vto'carr'v the same inward s'oth'atthfe inner side ofthe big-ht orloop of the needle thread will be away portion of the bobbin case flange 6 adjacent the lug 16 so as to engage the inneil side of the bight or loop of the needle thread and so holding that side while the beak 2 in its rotation carries the other side of the hightor loop over'the top of the bobbin case while the inner side of the bight or loop passes underneath the bo-bbin case to interlock with the bobbin thread.

The loop flange 17 in the present instance is-out or bent so that its upper andv lower surfaces slope downward from the upper edge of the bobbin case, the outer edge of the loop flange 17 being arranged to pass just inside and opposite a. beak flange 19 which extends from the beak 2 to approximately half way around the hook flange Ll, as shown in Figure 9. The beak flange y19 is cut on its outer edge to slope inwaiigland acts to guide the outer side of the bight or loop of the needle thread over the top of the bobbin case7 the outer side oi the bight or loop of the needle thread passing over the top of the bobbin case just previous to the time the enfl of the beak flanger 19passes the hooked end of the loop flange 17. The beak flange 19 also acts as a guard'to prevent the outer side of the big-ht or loop of the needle thread from engaging the loop flange 17, as the hight or loop of the needle thread passes over the top of the bobbin case, the outer edge of the loop flange 17 being below the upper edge of the .beak ange 19 and as itsupper surface slopes upwardfto the top of the bobbin case.

The bobbin case is provided with a bobbin thread tension device which inthe present instance comprises a flat steel spring 2O one end of which is secured to the bobbin case, above the bobbin case flange 6, by means of two small set screws 21. The other end of the tension spring' 2O is provided on its upper edge with a small bobbin thread notch 22 which extends underneath the loop flange 17 the top edge of the tension sping in the present instance being` cut away to permit the notched end of' the tension sj ring to engage theside of the bobbin case iuidernea h the loop flange.

In the present instance the side of the bobbin case is provided with a bobbin thread slot 23 situated in bach of and covered by the tension spring 20. The slot 23 extends from the upper edge of the bobbin case diagonally downward to point just above the bobbin .case flange G along which it extends,4 the same terminating in a bobbin thread hole 24'which is spaced-away from the thread notch 22 in the tension si ring 20.

rThebobbin thread 25 wound onthe bobbin 15 is 'threaded through the tension device bv drawing thebobbin'thread down through y the thread slot 23 to the thread hole 24 and forcing it in back of the free end oit the tension spring 20 by drawing the bobbin thread along the top of the tension spring until it reaches and passes out of the thread notch 22 near the end of' lthe tension spring.

Y Fromthe above description it will be seen that the bobbin thread passes from off' the bobbin and through the thread hole 24 which is situated approximately in the centre of the side of the bobbin case which facilirates a uniform pull of the thread from the bobbin. From the thread hole 24 the bobbin thread passes up to the threadnotch 22 between which points the thread is engaged by the .tension spring 20 forcing the same against the side of the bobbin case.A .The tension ot the spring 20can be easily lated by adjusting the inner set screw 21. The bobbin thread cannot come out 'of the thread notch 22 as the top of the tension spring, adjacent the end of the notch, coines in contact with theiinder side of the loop flange 1l' which is also undercut that tie outer edge ot the loop flange overhangs the.

top of the thread notch so as to further prevent the bobbin thread being pulled or slipped out of the notch 22.

The arrangement of the bobbin thread tension device makes it practically impossible for kthe bobbin thread once it is threaded therein to become dis alaced, the sanie isals-o very `easily threaded, it being only necessary to draw the thread into the tiireac slot 23 and theny underneath the loop flange 17 where it will engage the thread notch 22, the rear-end of the loop flange 17 being tapered toward the upper end of the thread slot 23 to accom plish this purpose. y

i Bue to the fact that the bobbin thread tension device is situated on thev side of the bobbin case a uniform pull on the bobbin thread is assured. It is further to be noted that the position of thev tension device under and adjacent the loop flange 17 assures that the saine will not act to catch the outer side of the bight or loop of the needle thread as the same is'protected by the beak flange 19 just previous to the time the outer side of the bight orloop passes over the top of the bobbin case.

The bobbin 15 ispreferably made in one piece as shownin Figure 2, the saine being` provided with a central bearing hole arranged to rotatably engage the bobbin case post lll. Both ends of the bobbin bearing ho-le are slightly enlarged and undercut to p form locking recesses 26 whichiare arranged to be engaged by spring acting locking arms i. i 2( j secured to the top of .the bobbin case Apost-.14.

.lie

the top of the locking arms 27 arey situatedv below the top edge of the bobbin and will in no way interfere with the bight or loop of' the needle thread passing over the same.`

It is also to be noted that the locking recosses 26 are so cut that either one will act to foi-ce inward the-locking arms 27 when the bobbin is placed over the bobbin case post le and either one of the recesses will also act to engage the locking arms 27 depending upon the direction of winding of the bobbin thread on the bobbinwhich way the bobbin is placedy in the bobbin case.

In order to remove the bobbin from the bobbin case it is usually customary to insert a pointed tool or instrument into the upper recess 26 and pry the same with a slight lifting pressure upwards. y

i ln order to overcomei friction between the bobbin case and the hook the bobbin case flange 6 is preferably cut both top `and bottoni as designated at 31 and 32 which are spaced at suitable intervals to correspond with the cut away portion of the bobbin case flange adjacent the lug 16.

The bobbin case flange 6 Vis also provided with a series of radial slots 33which act to hold oil to lubricate the groove or raceway 5. y

In the present instance the base of the hook is integrally secured to a shaft `34 which can be mounted in a suitable bearing and secured to a suitable gear not shown for rotating the same.

The rotary hook or loop taker above described is adapted for use in my copending sewing machine application Serial No. 410,472, filed September 15, 1920A and is capable of being rotated at a speed of nine thousand revolutions a minute upward to ten thousand revolutions a minute.

lhile the invention has been described with particular reference to the details of construction the same is not to be considered as limited thereto, as many changes can be made and still fall within the scope of the invention set forth in the following claims.

What l claim is:

l; A rotary hook or loop taker for sewing machines comprising a hook, a lioolc flange, a bobbin case, said flange and bobbin case having interlocking means to prevent tlie separation of the same and allow of the rotation of the bobbin case in the y liani e` and means for allowing tli-e flange to 2. A rotary hook or loop taker for sewing' machines, comprising a hook, a hook flange having a race way therein, a bobbin case,

a beading on saidbobbin case fitting in saidy race way and means` for allowing the flange to be swung in a plane at right angles to the axis of the rotary hook or loop taker to allow the bobbin case to be removed in a plane parallel the `axis of the rotary hook or loop taker.

y A rotary hook or loop taker for sew` ing machines, comprising a hook having a beak, a hook flange secured to said hook adjacent said beak, a raceway in said hook flange,y a boliibincase, a bobbin case flange on said bobbin case, the free end of said liiiiok flange being arranged to be sprung to admit the bobbiiicase flange on the bobbin case into engagement with the raceway in'- said hook flange. v

'--l.. A rotary hook or loop taker for sewingmachiiies. comprising a hook, a hook flange-secured at one end to said hook, a raceway in said hook flange, a bobbin case,

a bobbin case flange "on said bobbin case,l

tliefree end of said hook flange beingar ranged to be sprung toadniit the bobbin case flange on the bobbin case into engagey ment with the raceway in said hook flange, and means 'for locking the free end rof said hook flange after said bobbin case has been inserted in the raceway in said hook lflange.`

5.'A rotary hook or loop taker for sewing machines, comprising a hook having a beak, a hook flange vsecured to said hook adjacent said beak, a raceway in said hook flange, a bobbin case, a bobbin case flange onV end of said hook flange aftersaid bobbin case has been inserted in the raceway in said hook flange.

6. A rotary hook or loop taker for sewing machines comprising 'a hook, a hook flange, a raceway in said hook flange, a bobbin case,a bobbin case flange on said bobbin case, means for connecting said hook flange to said hook to'permit of the same beingFV sprung to admit the bobbin case flange on thevbobbin case into eiigagei'nent rwith the i'aceway on said hook flange,and means on f said hook to permit of ther same being sprung to admit or remove the bobbin case.

7. A rotary hook or loop taker for sewing machines comprising a hook, a hook flange secured at one end to said hook, ya

raceway in said hook flange` a bobbin case, a bobbin case flange on saidbobbin case,

the free end of said hook flangey being aii ranged to beA sprung to admit the bobbin i'aseflange on the bobbin case into engagement with the raceway in said hook flange,

and means on said hook to permit of the same being sprung to admit or remove the bobbin case.

8. Arotary hook or loop taker' for sewing` machinescomprising a hook having a beak, a hook flange secured to said hook adjacent said beak, a raceway in said hook flange, a bobbin case, a bobbin case flange on said bobbin case, the free end of said hook flange being arranged to.y be sprung to admit the bobbin case flange on the bobbin case into engagement with the raceway in said hook flange and means on said hook to permit of the same being sprung toadmit or remove the bobbin case.

9. A rotary hook or loop taker for sewing machines, comprising a bobbin case, a loop flange on said bobbin case, and a bobbinthreadtension device secured to said bobbin case, said bobbin thread tension device being arranged to extend underneath said loop flange and having a thread notch therein.

10. A rotary hook or loop taker for sewing machines, comprising a bobbin case, a loop flange having a hooked shaped end on said bobbin case, and a bobbin thread tension device arranged to engage the underside of said loop flange.

11. A rotary hook'or loop taker for sewing machines comprising abobbin case, an undercut loop flange on saidY bobbin case, and a bobbin thread tension device having a thread notch arranged to engage the undercut side of said loop flange.

12. A rotary hooker loop taker for sewing machines, comprising a bobbin case, a loop flange secured to the side of Said bobbin case, a-thread slot situated in the side of sa'id'bobbin case adjacent said loop flange, a thread tension spring secured at one end to the side of said bobbin case, the sideof said thread notch in the end of said thread tension spring, and means on said bobbin case for' engagingsaid thread notch.

14. A rota-ry hook or loop taker for sewinginachines Comprising a hook flange having a hook anda free end, a bobbin case, said bobbin case and flange havinginterlocking beading andraceway, said free end of the flange adapted to be sprung at right angles to the axis of the hook or loop taker, and means for springing the free end of the fla-nge.

15.y A rotary hook or loop taker for sewinfr machines, comprising` a hook flange having a hook and a free end, a` bobbin case, interlocking means betwe-en the bobbin case and the hook flange, said free end of` the hookflange adapted to be sprung at right angles to the axis ofl the hook or loop taker for allowing the bobbin case to be removed or inserted'and means for springing thefree end of the flange.

16. AA rotary hook or loop taker for sewing` machines, comprising. a hook flange having a hook and a free end, a bobbin case, interlocking means between' the bobbin case and the hook flange, said free end of the hook flange adapted to b-e sprung` at right angles to the axis of the loop taker for' allowingthe bobbin case tobe removed or inserted and means operated by a removable key fonspringing the free end of the flange.

17. A rotary hook-or loop taker for sewing machines comprising a hook flange having ahook and a free end, a bobbin case, said bobbin case and flange having interlocking beading. and raceway, and said'free end of the flange adapted to be sprung at right angles to the axis of the hook or loop taker. y

18. A' rotary hook or loop taker for sewing machines comprising a hook flange having a hook and free end,- a-bobbincase, and interlocking means between the bobbin case and the hook flange, andsaid free end of the hook 'flange adapted to be sprung at right angles to the axis of the hook or loop take-1' for allowing the bobbin case to be removed Iorinserted.

ln testimony whereof l have signed this specification in the presence of two subscribing witnesses. y l JAB/IES LEATHEM. lV-itnesses JACOB P. OLrvnR, L. F; GnIMns.

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